Night workers, business travelers, and colleges should be forewarned. Researchers at the Sleep Research Centre at the University of Surrey have concluded that staying up all night and sleeping during the day disrupts the rhythm of about one-third of an individual’s genes.
Published in Proceedings of the National Academy of Sciences, the researchers examined 22 participants in a dimly lit sleep lab for three days. On the first day, the researchers disrupted the participants’ sleep schedules to reset their biological clock to its native rhythm. On days two and three, the participants ate and slept on a 28-hour schedule until they were 12 hours out of sync of their normal biological clocks. The purpose was to mimic the effects of jet lag or working night shifts. Each day blood samples were drawn to analyze the timing of gene activity.
The blood tests revealed a decrease in gene expression. The first day with a normal sleep schedule, nearly 1,400 genes or 6.4 percent of all genes that were analyzed -- were in sync with the body’s rhythm. When the sleep schedules were shifted on days two and three, only 228 or 1 percent of the genes were analyzed.
Genes carry instructions for making proteins responsible for chemical signals and hormones, metabolism, inflammation, and immune response. Disrupted gene expression can be a sign of upset overall health.
“This research may help us to understand the negative health outcomes associated with shift work, jet lag, and other conditions in which the rhythms of our genes are disrupted,” said lead researcher Derk-Jan Dijk, professor of Sleep and Physiology and director of the Sleep Research Centre.
Shift workers are at higher risk for many health problems like obesity, diabetes, high blood pressure, heart disease, and cancer, Dijk said. This study does not directly connect heath issues and night shift, however, experts say it’s a start in understanding why sleep may have such a powerful impact on a person’s health.